Morphology of immatures of the thelytokous ant, Monomorium triviale Wheeler (Formicidae: Myrmicinae: Solenopsidini) with descriptions of the extraordinary last-instar queen larvae

The ant genus Monomorium is one of the most species-rich but taxonomically problematic groups in the hyperdiverse subfamily Myrmicinae. An East Asian species, M. triviale Wheeler, produces both reproductive queens and sterile workers via obligate thelytokous parthenogenesis. Here, we describe the immature forms of M. triviale based on light and scanning electron microscopy observations, with a note on the striking caste dimorphism in the last larval instar. The last-instar queen larvae were easily recognized by their large size, “aphaenogastroid” body shape, and rows of doorknob-like tubercles on the lateral and dorsal body surface. This type of queen-specific structure has not been found in ants in general, let alone congeneric species found in Japan. In stark contrast to the queen larvae, worker larvae showed a “pheidoloid” body shape and a body surface similar to other ants. The worker larvae were estimated to have three instars, consistent with previously described congeners. The pupae of both castes had no cocoon, a characteristic commonly described in other Myrmicinae species. In total, the developmental period from egg to adult worker averaged 59 days under 25°C. We discuss possible functions of the tubercles of queen larvae based on previous studies

The complete mitochondrial genome of a parthenogenetic ant Monomorium triviale (Hymenoptera: Formicidae)

Monomorium is one of the most species-rich yet taxonomically problematic ant genus. An East Asian species, M. triviale Wheeler, W.M., 1906, is reproduced by obligate thelytokous parthenogenesis and performs strict reproductive division of labor. We sequenced the M. triviale mitogenome using next-generation sequencing methods. The circular mitogenome of M. triviale was 16, 290 bp in length, consisting of 13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNAs, and a single non-coding region of 568 bp. The base composition was AT-biased (82%). Gene order rearrangements were detected and likely to be unique to the genus Monomorium. We announce the M. triviale mitogenome as additional genomic resources for elucidating phylogenetic and taxonomic problems of Monomorium and comparative genomics of parthenogenetic ant species

p53 family network and human cancer

Since the 1980s cancer is the leading cause of death in Japan. Most human cancers exhibit inactivation of the p53 network, either through direct mutation of p53,or through disruption of regulatory pathways essential for p53 function.The tumor suppressor gene p53 encodes a transcriptional activator as a nodal point for cellular responses to several stress conditions. p53 is one of the most highly connected nodes in the cell,and an attack on p53 by mutation will disrupt basic cellular functions, particularly responses to DNA damage and tumor-predisposing stresses. p63 and p73 are functionally and structurally related to the tumor suppressor p53. Recent findings from others and us have provided evidence for a broader role for the p53 family than were previously reported. In this review, we provide an overview of the networks controlled by the p53 family as a framework for developing p53 family-based strategies to treat cancer

Iterated maps for clarinet-like systems

The dynamical equations of clarinet-like systems are known to be reducible to a non-linear iterated map within reasonable approximations. This leads to time oscillations that are represented by square signals, analogous to the Raman regime for string instruments. In this article, we study in more detail the properties of the corresponding non-linear iterations, with emphasis on the geometrical constructions that can be used to classify the various solutions (for instance with or without reed beating) as well as on the periodicity windows that occur within the chaotic region. In particular, we find a regime where period tripling occurs and examine the conditions for intermittency. We also show that, while the direct observation of the iteration function does not reveal much on the oscillation regime of the instrument, the graph of the high order iterates directly gives visible information on the oscillation regime (characterization of the number of period doubligs, chaotic behaviour, etc.)

Effects of Leg Motor Imagery Combined With Electrical Stimulation on Plasticity of Corticospinal Excitability and Spinal Reciprocal Inhibition

Motor imagery (MI) combined with electrical stimulation (ES) enhances upper-limb corticospinal excitability. However, its after-effects on both lower limb corticospinal excitability and spinal reciprocal inhibition remain unknown. We aimed to investigate the effects of MI combined with peripheral nerve ES (MI + ES) on the plasticity of lower limb corticospinal excitability and spinal reciprocal inhibition. Seventeen healthy individuals performed the following three tasks on different days, in a random order: (1) MI alone; (2) ES alone; and (3) MI + ES. The MI task consisted of repetitive right ankle dorsiflexion for 20 min. ES was percutaneously applied to the common peroneal nerve at a frequency of 100 Hz and intensity of 120% of the sensory threshold of the tibialis anterior (TA) muscle. We examined changes in motor-evoked potential (MEP) of the TA (task-related muscle) and soleus muscle (SOL; task-unrelated muscle). We also examined disynaptic reciprocal inhibition before, immediately after, and 10, 20, and 30 min after the task. MI + ES significantly increased TA MEPs immediately and 10 min after the task compared with baseline, but did not change the task-unrelated muscle (SOL) MEPs. MI + ES resulted in a significant increase in the magnitude of reciprocal inhibition immediately and 10 min after the task compared with baseline. MI and ES alone did not affect TA MEPs or reciprocal inhibition. MI combined with ES is effective in inducing plastic changes in lower limb corticospinal excitability and reciprocal Ia inhibition

Prediction of p53 target genes based on integrative analysis of chromatin immunoprecipitated and sequenced tags，by using Galaxy，a web-based interactive platform for large-scale genome analysis

Chromatin immunoprecipitation (ChIP) followed by sequencing of immunoprecipitated DNA fragments is the high throughput method for identifying transcription factor binding sites. In one such method, ChIP PET, paired end ditags (PETs) derived from both ends of the immunoprecipitated DNA fragments are sequenced and mapped to the genome. We report here the prediction of p53 target genes by meta analyzing tags of p53 ChIP PET and by combining with other genomic annotations, using Galaxy, a web based platform for large scale genome analysis. We found 327 of p53 binding sites on the genome of 5-fluorouracil (5-FU)-treated HCT116 colon cancer cells by searching the total 65,509 PETs for PET clusters. The search for p53 target gene, which focused on PET clusters with computationally-predicted p53 binding motif, identified 20 of putative p53 target genes as well as 11 of known p53 targets. Another search for p53 target genes, which focused on PET clusters located within 50-kb flanking regions of transcription start sites of genes, identified 278 of Refseq genes, 79 of non-coding RNAs and 5 of microRNAs as p53 targets which included lots of known validated targets. Our results indicate that sequencing-based ChIP analysis combined with the existing genome annotation is effective method to predict p53 binding loci and target genes, and also show that the Galaxy platform is well-suited for multiple-type analyses and visualization of ChIP data, leading to functional annotation of transcription factor binding sites

Revealing the Anti-Tumor Effect of Artificial miRNA p-27-5p on Human Breast Carcinoma Cell Line T-47D

microRNAs (miRNAs) cause mRNA degradation or translation suppression of their target genes. Previous studies have found direct involvement of miRNAs in cancer initiation and progression. Artificial miRNAs, designed to target single or multiple genes of interest, provide a new therapeutic strategy for cancer. This study investigates the anti-tumor effect of a novel artificial miRNA, miR P-27-5p, on breast cancer. In this study, we reveal that miR P-27-5p downregulates the differential gene expressions associated with the protein modification process and regulation of cell cycle in T-47D cells. Introduction of this novel artificial miRNA, miR P-27-5p, into breast cell lines inhibits cell proliferation and induces the first “gap” phase (G1) cell cycle arrest in cancer cell lines but does not affect normal breast cells. We further show that miR P-27-5p targets the 3′-untranslated mRNA region (3′-UTR) of cyclin-dependent kinase 4 (CDK4) and reduces both the mRNA and protein level of CDK4, which in turn, interferes with phosphorylation of the retinoblastoma protein (RB1). Overall, our data suggest that the effects of miR p-27-5p on cell proliferation and G1 cell cycle arrest are through the downregulation of CDK4 and the suppression of RB1 phosphorylation. This study opens avenues for future therapies targeting breast cancer